• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
• /
• v.16 no.1
• /
• pp.28-32
• /
• 2005

Background and Objectives : The most important two factors of the voice production are the respiratory function which is the power source of voice and the glottic closure that transform the air flow into sound signals. The purpose of this study was to investigate the differences between trained singers and untrained controls under varying intensity at a constant vocal pitch by simulataneous using the airway interruption method and electroglottography(EGG). Materials and Methods : Under two different intensity condition at a constant vocal pitch(/G/), 20(Male 10, Female 10) trained singers were studied. Mean flow rate(MFR), subglottic pressure(Psub) and intensity were measured with aerodynamic test using the Phonatory function analyzer. Closed quotients(CQ), jitter and shimmer were also investigated by electroglottography using Lx speech studio. These data were compared with that of normal controls. Results : MFR and Psub were increased on high intensity condition in all subject groups but there was no statistically significance. Statistically significant increasing of CQ. were observed in male trained singers on high intensity condition (untrained male : 51.31${\pm}$3.70%, trained male :55.52${\pm}$6.07%, p=.039). Shimmer percent, one of the phonatory stability parameters, was also decreased statistically in all subject groups(p<.001). Conclusion : The trained singers' phonation was more efficient than untrained singers. The result means that the trained singers can increase the loudness with little changing of mean flow rate, subglottic pressure but more increasing of glottic closed quotients.

• Journal of Institute of Control, Robotics and Systems
• /
• v.13 no.8
• /
• pp.726-734
• /
• 2007

Generally, a mobile robot is moved by original input programs. However, it is very hard for a non-expert to change the program generating the moving path of a mobile robot, because he doesn't know almost the teaching command and operating method for driving the robot. Therefore, the teaching method with speech command for a handicapped person without hands or a non-expert without an expert knowledge to generate the path is required gradually. In this study, for easily teaching the moving path of the autonomous mobile robot, the autonomous mobile robot with the function of speech recognition is developed. The use of human voice as the teaching method provides more convenient user-interface for mobile robot. To implement the teaching function, the designed robot system is composed of three separated control modules, which are speech preprocessing module, DC servo motor control module, and main control module. In this study, we design and implement a speaker dependent isolated word recognition system for creating moving path of an autonomous mobile robot in the unknown environment. The system uses word-level Hidden Markov Models(HMM) for designated command vocabularies to control a mobile robot, and it has postprocessing by neural network according to the condition based on confidence score. As the spectral analysis method, we use a filter-bank analysis model to extract of features of the voice. The proposed word recognition system is tested using 33 Korean words for control of the mobile robot navigation, and we also evaluate the performance of navigation of a mobile robot using only voice command.

• The Journal of the Acoustical Society of Korea
• /
• v.19 no.5
• /
• pp.3-8
• /
• 2000

In this paper, we studied design and implementation of a robust speech recognition system in noisy car environment. The reference pattern used in the system is DMS(Dynamic Multi-Section). Two separate acoustic models, which are selected automatically depending on the noisy car environment for the speech in a car moving at below 80km/h and over 80km/h are proposed. PLP(Perceptual Linear Predictive) of order 13 is used for the feature vector and OSDP (One-Stage Dynamic Programming) is used for decoding. The system also has the function of editing the phone-book for voice dialing. The system yields a recognition rate of 89.75% for male speakers in SI (speaker independent) mode in a car running on a cemented express way at over 80km/h with a vocabulary of 33 words. The system also yields a recognition rate of 92.29% for male speakers in SI mode in a car running on a paved express way at over 80km/h.

• Phonetics and Speech Sciences
• /
• v.6 no.3
• /
• pp.3-12
• /
• 2014

Larynx plays an important role in phonation and protection of the respiratory tract during swallowing. The reduced anatomical and physiological function in elevation of larynx and glottis closure can cause problems in voice and swallowing. The present study investigated the Korean version of handicap index of dysphagia in elderly Koreans. Therefore, 60 normal elderly Koreans ranged from 65 to 95 and 20 normal Korean young adults aged from 20 to 25 were participated in this study to compare total (T), physical (P), functional (F), and emotional (E) index scores between two groups as well as among sub groups (60s, 70s, 80s) in elderly. For swallowing, total and sub dysphagia handicap index (DHI) scores, voice quality during /a/phonation following swallowing (saliva and water), intensity of coughing, and L-DDK were measured. The results showed that functional (P), physical (P), emotional (E) scores as well as total (T) score were significantly different between young adults and old adults in DHI(p<.05). Additionally, there was a negative correlation between total DHI score and intensity of coughing (r=-.51) as well as L-DDK (r=-.70). These findings suggest that a slow rate in vocal fold adduction and reduced intensity of coughing in the elderly affect swallowing function. Thus, recently translated Korean version of DHI may be useful as supplement in evaluating the swallowing problems in elderly people.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2002.11a
• /
• pp.682-685
• /
• 2002

VoIP(Voice over IP) Technology is highlighted because of easy adopting the value added services related voice In this paper, we described the Internet telephony service based on SIP. Especially, we described the extension for re-INVITE function. Re-INVITE function is useful for cail transfer service or conference service.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2015.10a
• /
• pp.783-786
• /
• 2015

Hole attack, which is disturbed transmission function through change of routing information, can cause critical results for MANET as non-infrastructure network. Backhole attack, as a typical hole attack, is one malicious attack which is disabled network transmission function by assumption of transmission data through modification of routing information. It is very important to evaluate transmission performance caused by blackhole attack, because transmission performance of MANET is affective with blackhole attack. In this paper, transmission performance is analyzed with MANET under multiple blackhole attacks caused multiple blackhole nodes. Computer simulation based on NS-2 is used as analysis tool and voice traffic is considered ad application service on MANET.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2017.10a
• /
• pp.96-97
• /
• 2017

When a new student, a guest, or a student who first visited a school wants to know information about the school, he / she searches through a smartphone or a tablet. However, if you visit the homepage of the school, you do not know exactly where the information you want to find is located, and you spend a lot of time. In this paper, we develop a school guidance system using Alexa with speech recognition function. Divide the school guidance system into college introduction, major, college activities, and entrance information topics, and fill in the details by topic. In the lambda function of Amazon Web Services, we use Node.js to create information on topics and provide information to users by voice.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2014.05a
• /
• pp.578-581
• /
• 2014

Blackhole attack, a kinds of attacks to routing function, can cause critical effects to network transmission function, Especially, on MANET(Mobile Ad-hoc Network) which it is not easy to prepare functions to respond malicious intrusion, transmission functions of entire networks could be degraded. In this paper, effects of blackhole attack to network transmission performance is analyzed on lattice structured MANET. Specially, performance is measured for various location of blackhole attack on lattice MANET, and compared with the performance of random structured MANET. This paper is done with computer simulation, VoIP(Voice over Internet Protocol) traffic is used in simulation. The results of this paper can be used for data to deal with blackhole attack.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.19 no.1
• /
• pp.179-185
• /
• 2019

A core technology of social robot is voice recognition and dialogue engine technology, but too much money is needed for development and an implementation of robot's conversation function is difficult resulting from insufficiency of performance. Dialogue function's implementation between human and robot can be possible due to advance of cloud AI technology and several company's supply of their open API. In this paper, current intelligent social robot technology trend is investigated and effective social robot system architecture is designed. Also an effective analysis and design method of social robot system will be presented by showing user requirement analysis using object-oriented method, flowchart and screen design.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
• /
• v.8 no.1
• /
• pp.27-32
• /
• 1997

Recently, many people suffering from voice color change visit otolaryngologist. There is no specific data which can be evaluated objectively for voice color change in korean. In aerodynamic study, maximum phonation time, mean air flow rate, phonatory flow volume and subglottal pressure were tested by using Aerophone II voice function analyzer in korean. 112 male and 122 female aged from 10 to 69 years were randomly selected. Maximum phonation time was 20.8${\pm}$6.4sec in male and 17.2${\pm}$4.1sec in female. Mean air flow rate was 167.1${\pm}$61.4ml/sec. in male and 129.6${\pm}$49.3ml/sec in female. Phonatory flow volume was 3184.5${\pm}$646.0ml in male and 2122.1${\pm}$670.5ml in female. Subglottal pressure was 4.1${\pm}$1.8 cmH2O in male and 3.5${\pm}$1.4cm $H_2O$ in female. There was no statistically significant difference among age groups in all above results.